Short answer
You become Muslim by believing in your heart that there is no god but Allah and that Muhammad ﷺ is His messenger, and saying the shahada (declaration of faith) with your tongue. No witnesses, fee, imam or certificate are needed, and it is the same for men and women.
In the Hanafi school, faith is belief in the heart affirmed by the tongue. Saying the shahada with understanding and sincere belief makes a person Muslim at once. Saying it in front of others is good, so that people can treat you as a Muslim, but it is not a condition. Hanafi texts add that a person from another religion should also disown any belief that contradicts Islam, which the shahada already implies.
The four schools agree on this.
Explanation
There is no ceremony to wait for. Once you believe that Allah is the one true God and that Muhammad ﷺ is His final messenger, say: Ash-hadu an la ilaha illallah, wa ash-hadu anna Muhammadan rasulullah (I bear witness that there is no god but Allah, and I bear witness that Muhammad is the messenger of Allah). Our shahada page has the Arabic, the pronunciation and the meaning.
It takes as long as it takes to say one sentence. Many people say it at a mosque so that the community can welcome them, and some mosques give a certificate. A certificate helps later with things like an umrah visa or a nikah, but your Islam does not depend on it. Women and men say exactly the same words. The four schools agree that no witness or ceremony is a condition.
- You do not need to know Arabic or the whole religion first.
- You do not need to change your name or your nationality.
- Ghusl (a full bath) after the shahada is recommended, and required if you were in a state that needs ghusl. See ghusl after converting.
Many new Muslims call themselves reverts. The word comes from the hadith that every child is born on the fitrah, the natural inclination to know and worship the one God. Revert and convert mean the same thing in practice, and both are fine to use.
After the shahada, learn the pillars step by step: start with the five daily prayers, using our how to pray guide, and read the new Muslim guide at your own pace.
The evidence
Quran, Surah An-Nisaa 4:136
يَٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوٓا۟ ءَامِنُوا۟ بِٱللَّهِ وَرَسُولِهِۦ وَٱلْكِتَٰبِ ٱلَّذِى نَزَّلَ عَلَىٰ رَسُولِهِۦ وَٱلْكِتَٰبِ ٱلَّذِىٓ أَنزَلَ مِن قَبْلُ ۚ وَمَن يَكْفُرْ بِٱللَّهِ وَمَلَٰٓئِكَتِهِۦ وَكُتُبِهِۦ وَرُسُلِهِۦ وَٱلْيَوْمِ ٱلْءَاخِرِ فَقَدْ ضَلَّ ضَلَٰلًۢا بَعِيدًا ﴿١٣٦﴾
O you who have believed, believe in Allah and His Messenger and the Book that He sent down upon His Messenger and the Scripture which He sent down before. And whoever disbelieves in Allah, His angels, His books, His messengers, and the Last Day has certainly gone far astray.
Faith means believing in Allah, His messenger and the scriptures He sent.
Quran, Surah Ar-Room 30:30
فَأَقِمْ وَجْهَكَ لِلدِّينِ حَنِيفًۭا ۚ فِطْرَتَ ٱللَّهِ ٱلَّتِى فَطَرَ ٱلنَّاسَ عَلَيْهَا ۚ لَا تَبْدِيلَ لِخَلْقِ ٱللَّهِ ۚ ذَٰلِكَ ٱلدِّينُ ٱلْقَيِّمُ وَلَٰكِنَّ أَكْثَرَ ٱلنَّاسِ لَا يَعْلَمُونَ ﴿٣٠﴾
So direct your face toward the religion, inclining to truth. [Adhere to] the fitrah of Allah upon which He has created [all] people. No change should there be in the creation of Allah. That is the correct religion, but most of the people do not know.
Every person is created with a natural disposition toward the one God, the basis of the word revert.
Sahih al-Bukhari 8
Sahih... بني الإسلام على خمس شهادة أن لا إله إلا الله ...
"Islam is built on five: bearing witness that there is no god but Allah and that Muhammad is the messenger of Allah, establishing prayer, giving zakat, hajj and fasting Ramadan."
The shahada is the first pillar and the doorway into Islam.
Sahih al-Bukhari 1358
Sahih... ما من مولود إلا يولد على الفطرة فأبواه يهودانه ...
"Every child is born upon the fitrah, then his parents make him a Jew, a Christian or a Magian."
The source of the idea that a person who accepts Islam is returning to their natural state.
Where the ruling is recorded
- al-Fiqh al-Akbar, the section on the definition of iman. Abu Hanifa defines faith as affirmation by the tongue and belief in the heart.
- Radd al-Muhtar (Ibn Abidin), Kitab al-Jihad, Bab al-Murtadd, discussion of how a person becomes Muslim. Discusses what statements establish a person's Islam.
This answer is pending review by the scholars on our team. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.